Film and cameras that are all in one, commonly referred to as single-use or one-time-use cameras, have become well known. Typically, the one-time-use camera is a simple point-and-shoot type comprising a plastic main body part which supports a conventional film cartridge in a cartridge receiving chamber, a film take-up spool in a film supply chamber, a fixed-focus taking lens, a film metering mechanism with a rotatably supported metering sprocket that engages the filmstrip, a manually rotatable thumbwheel rotatably engaged with a film spool inside the film cartridge, a single-blade shutter, a manually depressible shutter release button, a rotatable frame counter for indicating the number of exposures remaining for picture-taking, a direct see-through viewfinder, and in some models an electronic flash. A pair of plastic front and rear cover parts house the main body part between them to complete the camera unit. The rear cover part connects to the main body part and/or to the front cover part to make the main body part light-tight. A decorative cardboard outer box or label at least partially covers the camera unit and has respective openings for the taking lens, etc.
After each picture is taken with the one-time-use camera, the photographer manually rotates the thumbwheel in a film winding direction to similarly rotate the film spool inside the film cartridge. This winds an exposed section of the filmstrip into the film cartridge. The rewinding movement of the filmstrip the equivalent of slightly more than one frame width rotates the metering sprocket in engagement with the filmstrip to decrement the frame counter to its next lower-numbered setting and to pivot a metering lever into engagement with the thumbwheel in order to prevent further manual rotation of the thumbwheel. Manually depressing the shutter release button to take another picture pivots the metering lever out of engagement with the thumbwheel to permit renewed rotation of the thumbwheel. When the maximum number of exposures available on the filmstrip are exposed, and the filmstrip is completely wound off the take-up spool and wound into the film cartridge, the one-time-use camera is given to a photofinisher who tears the outer box off the camera unit, separates the rear cover part from the main body part, and removes the film cartridge with the exposed filmstrip from the cartridge receiving chamber. Then, he removes the exposed filmstrip from the film cartridge to develop the negatives and make prints for the customer.
As shown in prior art U.S. Pat. No. 4,954,857 issued Sep. 4, 1990 discloses a one-time-use camera comprising a main body part having a backframe opening for exposing successive sections of a filmstrip, a metering sprocket rotatably supported on the main body part proximate the backframe opening and having respective teeth that can project through individual perforations in the filmstrip to engage successive sections of the filmstrip at the backframe opening, and a rear cover part having a plurality of parallel film guide ribs longitudinally extending to guide successive sections of the filmstrip over the backframe opening. There is nothing provided in the area that each one of the teeth project through the perforations in the filmstrip, which would retain successive sections of the filmstrip in engagement with said metering sprocket. However, as depicted in U.S. Pat. No. 4,477,162 issued Oct. 16, 1984, it is known for a rear cover part to include a short groove for this purpose.